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Wireshark-users: [Wireshark-users] Question on Fin/ack

From: "Jamie Crawford" <jamie.d.crawford@xxxxxxxxx>
Date: Mon, 26 Mar 2007 14:24:00 -0500
Hello,
I've got a application that probes a wireless printer to make sure it can communicate over tcp 6101.  Once that it sees that it can communicate over that port, it will then send it's print job.  But for some reason, the printer hangs up and won't accept any more connections for 60 seconds. Heres what the conversation looks like.  Should the server just send a fin,ack to kill the session off?  I figured you would first send a fin, and then get a fin,ack back from the printer?
 
 
server 29515 -> printer 6101 syn
printer 6101 -> server 29515 syn,ack
server 29515 -> printer 6101 ack
server 29515 -> printer 6101 fin,ack
server 29517 -> printer 6101 syn
printer 6101 -> server 29515 ack (TCP ZEROWINDOW)
printer 6101 -> server 29517 rst,ack
server 29517 -> printer 6101 syn
printer 6101 -> server 29517 rst,ack
server 29517 -> printer 6101 syn
printer 6101 -> server 29517 rst,ack
server 29517 -> printer 6101 syn
printer 6101 -> server 29517 rst,ack
server 29517 -> printer 6101 syn
 
start over..same cycle....
 
thanks in advance,
j